MYOLOGY. 63 
Its use is to assist the former muscle in closing the extremity of the rectum in 
defecation. 
Erector or compressor penis, a long and flat muscle, arises from the inner 
surface of the tuber ischii, and from the insertion of the great or inferior 
sacro-sciatic ligament: it is inserted into the fibrous membrane of the corpus 
cavernosum of the penis. Its use is to draw down and facilitate the erection 
of the penis. 
Accelerator urine, or ejaculator seminis, extends from the front of the 
rectum to the back part of the scrotum, and is attached to its fellow along 
the mesial line. Use: to expel the last drops of semen or urine. 
Transversalis perinei is a thin and weak muscle, sometimes wanting: it 
arises from the inside of the tuberosity of the ischium above the erector 
penis muscle, and is inserted into the central portion of the perineum 
behind the accelerator urine. It supports and raises the anus, assisting 
also in defecation. 
Levator ant is a flat, thin, and broad muscle, placed at the inferior and 
lateral part of the pelvis. It arises by three origins, the first from the pos- 
terior part of the symphysis pubis, the second from the obturator fascia and 
the ilium, the third from the inner surface of the ischium: it is inserted 
into the central point of the perinzeum, and into the fore part of the rectum, 
into the sides of the rectum, and into the back part of the rectum, as also 
into the two last bones of the coccyx. Its use is to raise and draw forward 
the rectum, as also to close it; it also assists powerfully in the evacuation 
of feces, urine, and semen. 
The coccygeus is a small triangular muscle posterior to the levator ani: it 
arises from the inner surface of the spine of the ischium, and is inserted 
into the extremity of the sacrum and side of the coccyx. It supports and 
raises the coccyx in defecation, and assists in closing the inferior and pos- 
terior part of the pelvis. 
Pl. 124, fig. 15°, obliquus internus; *, rectus. abdominis. fg. 17°, 
obliquus externus. 
Pl. 125, fig. 19”, linea alba; ”, rectus abdominis crossed by the liner 
transversales ; **, transversus abdominis. 
Pl. 126, jig. 20“, transversus abdominis. 
Pl. 127, fig. 9°, obliquus externus; *, femoral ring; °, obliquus internus; 
‘section of the aponeurosis of the obliquus externus; ™, linea alba. 
Fig.10***, obliquus internus; *“°, transversus abdominis; *, pyramidalis; 
*, rectus abdominis; °, lhnea alba. fig. 11’, muscular portion of the 
diaphragm ; °, central tendon or phrenic centre; °, left crus; *, right crus; 
* foramen venz cave; *, opening for the cesophagus; ’, do. for the aorta ; 
*, the posterior fibres of the true diaphragm, arising from °, the ligamentum 
arcuatum ; *, psoas parvus; ", psoas magnus; ™, quadratus lumborum; 
** ihacus internus. 
F. Muscles of the Superior Extremities. 
The upper extremity is connected with the trunk by the sterno-clavicular 
ligaments, and by eleven muscles, all of which have been already described. 
ICONOGRAPHIC ENCYCLOPADIA.—VOL. II. 49 769 
